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9. Auto-blank
permits you to speed up your testing. This unique operator-controlled feature
allows quick, multiple sample readings
without your having to reinsert the blank tube
between each measurement
To access this feature, the On/Off switch must be pressed promptly, once, in Step 1 above,
when the display reads:
MODEL 942
(NAME OF TEST)
The display will then read:
AUTO BLANK ON
(NAME OF TEST)
If the Auto-blank display does not appear, the On/Off switch was not pressed at the correct
time, causing the instrument to be turned off. Turn it back on, and try again.
After the Auto-blank display disappears, the INSERT BLANK display will appear as in Step 1.
Follow instructions as previously given in Section 3, Steps 2 through 4. When the tube is
removed in Step 4, the instrument will prompt INSERT SAMPLE TUBE (meaning the NEXT
Sample Tube).
Insert your next Sample Tube. The instrument will now allow you to insert as many Sample
Tubes as you wish, without having to first insert the BLANK Tube each time.
To deactivate the Auto-blank feature, turn the instrument off at any point, and activate the
instrument again without accessing the Auto-blank feature.
NOTE: While the Auto-blank feature can be a significant time-saver in many situations, be
aware that the accuracy of the Auto-blank feature depends on a number of factors. It
assumes that the color of the blank would not change in the time Auto-blank is used, that
subsequent Sample Tubes have stable colors, that elapsed time and temperature changes
during the testing period would not effect the results, etc. If you have any reservations that
one or more of the above factors could influence the accuracy using the Auto-blank feature,
use the standard method in Section 3 instead.
